Eliminating the Low-Prevalence Effect in Visual Search With a Remarkably Simple Strategy

Area of Science:

• Cognitive Psychology
• Visual Perception
• Human Factors

Background:

• The low-prevalence effect describes the disproportionately high rate of missed rare targets in visual search.
• This phenomenon has significant implications for public safety and health, yet interventions have been challenging.
• Existing visual search tasks typically instruct participants to find a target's presence or absence.

Purpose of the Study:

• To investigate a novel cognitive strategy for reducing the low-prevalence effect in visual search.
• To determine if a 'similarity search' approach can mitigate the missed detection of rare targets.
• To assess the effectiveness of this strategy across multiple experimental trials.

Main Methods:

• Three experiments were conducted with adult participants (N=41, 40, 44).
• Participants performed visual search tasks under two conditions: standard search instructions and a novel 'similarity search' instruction.
• Similarity search required participants to identify the most similar item to a target on each trial, irrespective of target presence.

Main Results:

• Strong low-prevalence effects were observed when participants followed standard search instructions.
• Under identical visual conditions, the low-prevalence effect was not detected when participants employed the similarity search strategy.
• This reduction in the low-prevalence effect was consistently observed across all three experiments.

Conclusions:

• A simple, untrained cognitive strategy ('similarity search') can dramatically reduce the low-prevalence effect in visual search.
• This finding offers a promising, low-cost intervention for improving detection accuracy in critical safety and health applications.
• The results highlight the importance of task instructions in shaping visual search performance and mitigating common search errors.